Light bulb



FIG. 1 is a top perspective view of a light bulb in accordance with the present design;

FIG. 2 is a side view thereof;

FIG. 3 is a top view thereof; and,

FIG. 4 is a bottom view thereof.

The broken lines are for illustrative purposes only and form no part of the claimed design. Any shading forms no part of the claimed design and is provided to illustrate contour only and is not an indication of texture, gloss, and the like. 

CLAIM We claim the ornamental design for a light bulb, as shown and described. 